Japanese Utility Model Laid-Open Publication No. H05-195 (Patent Document 1) shows an example of a transformable toy capable of changing its figure from a state where a toy doll is riding on a movable toy to a toy robot having a configuration different from that of the toy doll by transforming at least a part of the movable toy and mounting it on the toy doll. In this disclosure, the toy robot is constituted merely by disassembling the movable toy to obtain an assembly constituent section and mounting the obtained constituent section onto the toy doll.
Japanese Utility Model Laid-Open Publication No. S60-102092 (Patent Document 2), Japanese Utility Model Laid-Open Publication No. S61-77094 (Patent Document 3), and Japanese Utility Model Laid-Open Publication No. S64-20891 (Patent Document 4) show examples of a transformable toy constituting a toy robot by transforming an autobicycle.
FIG. 2 of Japanese Utility Model Laid-Open Publication No. S61-45993 shows an example of a toy foot structure in which a foot having a tiptoe and a heel is mounted to a shin section in such a manner that the foot section can incline and move in a back and forth direction with respect to the shin section. This conventional toy foot structure is applied to a doll-type toy robot which opens its pair of leg sections back and forth, enabling the tiptoe and the heel of the foot to be always in full contact with a setting surface when the pair of leg sections are opened back and forth.
FIGS. 1 through 3 of the Utility Model Registration Publication No. 3079299 show an example of a toy foot structure in which an ankle includes a spherical portion, a shin section includes a spherical seat for receiving the spherical portion so that a foot can freely rotate with respect to the shin section.
[Patent Document 1]
    Japanese Utility Model Laid-Open Publication No. H05-195, FIGS. 1-10[Patent Document 2]    Japanese Utility Model Laid-Open Publication No. S60-102092, FIG. 5[Patent Document 3]    Japanese Utility Model Laid-Open Publication No. S61-77094, FIGS. 2, 3[Patent Documents 4]    Japanese Utility Model Laid-Open Publication No. S64-20891, FIG. 3[Patent Document 5]    Japanese Utility Model Laid-Open Publication No. S61-45993, FIG. 2[Patent Document 6]    Utility Model Registration Publication No. 3079299, FIGS. 1-3